From 669599cfd7c2d316e9086d31e1ccaab5b5964adb Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Tue, 24 Jan 2017 00:29:40 +0100
Subject: [PATCH] Add audio_mix to libretro-common

---
 Makefile.common                           |  3 +-
 griffin/griffin.c                         |  1 +
 libretro-common/audio/audio_mix.c         | 68 +++++++++++++++++++++++
 libretro-common/include/audio/audio_mix.h | 46 +++++++++++++++
 4 files changed, 117 insertions(+), 1 deletion(-)
 create mode 100644 libretro-common/audio/audio_mix.c
 create mode 100644 libretro-common/include/audio/audio_mix.h

diff --git a/Makefile.common b/Makefile.common
index f9247a28bb..691851b525 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -453,7 +453,8 @@ ifeq ($(HAVE_NEON),1)
 endif
 
 OBJ += $(LIBRETRO_COMM_DIR)/audio/conversion/s16_to_float.o \
-       $(LIBRETRO_COMM_DIR)/audio/conversion/float_to_s16.o
+       $(LIBRETRO_COMM_DIR)/audio/conversion/float_to_s16.o \
+		 $(LIBRETRO_COMM_DIR)/audio/audio_mix.o
 
 ifeq ($(HAVE_NEON),1)
    OBJ += $(LIBRETRO_COMM_DIR)/audio/conversion/s16_to_float_neon.o \
diff --git a/griffin/griffin.c b/griffin/griffin.c
index da7724432d..c2f8b31a49 100644
--- a/griffin/griffin.c
+++ b/griffin/griffin.c
@@ -1112,6 +1112,7 @@ XML
 ============================================================ */
 #include "../libretro-common/audio/conversion/s16_to_float.c"
 #include "../libretro-common/audio/conversion/float_to_s16.c"
+#include "../libretro-common/audio/audio_mix.c"
 
 /*============================================================
  LIBRETRODB
diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
new file mode 100644
index 0000000000..ef7066c6cd
--- /dev/null
+++ b/libretro-common/audio/audio_mix.c
@@ -0,0 +1,68 @@
+/* Copyright  (C) 2010-2017 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (audio_mix.c).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <audio/audio_mix.h>
+
+#if defined(__SSE2__)
+#include <emmintrin.h>
+#elif defined(__ALTIVEC__)
+#include <altivec.h>
+#endif
+
+void audio_mix_volume_C(float *out, const float *in, float vol, size_t samples)
+{
+   size_t i;
+   for (i = 0; i < samples; i++)
+      out[i] += in[i] * vol;
+}
+
+#ifdef __SSE2__
+void audio_mix_volume_SSE2(float *out, const float *in, float vol, size_t samples)
+{
+   size_t i;
+   __m128 volume = _mm_set1_ps(vol);
+
+   for (i = 0; i + 16 <= samples; i += 16, out += 16, in += 16)
+   {
+      unsigned j;
+      __m128 input[4] = {
+         _mm_loadu_ps(out +  0),
+         _mm_loadu_ps(out +  4),
+         _mm_loadu_ps(out +  8),
+         _mm_loadu_ps(out + 12),
+      };
+
+      __m128 additive[4] = {
+         _mm_mul_ps(volume, _mm_loadu_ps(in +  0)),
+         _mm_mul_ps(volume, _mm_loadu_ps(in +  4)),
+         _mm_mul_ps(volume, _mm_loadu_ps(in +  8)),
+         _mm_mul_ps(volume, _mm_loadu_ps(in + 12)),
+      };
+
+      for (j = 0; j < 4; j++)
+         _mm_storeu_ps(out + 4 * j, _mm_add_ps(input[j], additive[j]));
+   }
+
+   audio_mix_volume_C(out, in, vol, samples - i);
+}
+#endif
+
diff --git a/libretro-common/include/audio/audio_mix.h b/libretro-common/include/audio/audio_mix.h
new file mode 100644
index 0000000000..045e5e0d9d
--- /dev/null
+++ b/libretro-common/include/audio/audio_mix.h
@@ -0,0 +1,46 @@
+/* Copyright  (C) 2010-2017 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (audio_mix.h).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __LIBRETRO_SDK_AUDIO_MIX_H__
+#define __LIBRETRO_SDK_AUDIO_MIX_H__
+
+#include <retro_common_api.h>
+
+#include <stdint.h>
+#include <stddef.h>
+
+RETRO_BEGIN_DECLS
+
+#if defined(__SSE2__)
+#define audio_mix_volume           audio_mix_volume_SSE2
+
+void audio_mix_volume_SSE2(float *out,
+      const float *in, float vol, size_t samples);
+#else
+#define audio_mix_volume           audio_mix_volume_C
+#endif
+
+void audio_mix_volume_C(float *dst, const float *src, float vol, size_t samples);
+
+RETRO_END_DECLS
+
+#endif